After 8 years at WhatsApp, I have decided to move on and start a new chapter in my life.

I am very fortunate at my age to have the flexibility to take new risks and focus on what I'm passionate about. I've decided to start a non-profit focused at the intersection of nonprofit, technology and communications. It's something I've thought about for a while, and now it's time to just focus and execute. I'll have more to share in the coming months.

This decision is, of course, a tough one. I'm proud of what our team has accomplished in only a few years, and it's humbling to see that so many people rely on WhatsApp every day.

Acton started WhatsApp with CEO Jan Koum in 2009 after the pair had met working at Yahoo. The team struck it big in 2014 when Facebook agreed to pay $19 billion to buy it, although the price ended up rising to $22 billion thanks to share-based components to the deal.

Today, WhatsApp is the world's most-used messaging app today with over one billion monthly users, that's more than double the 450 million it had at the date of the acquisition. At that time WhatsApp was little-known in the U.S. since most of its users were based overseas.